Thanks Dabnis for your helpful advice and support.
I found a leak in the Racor MD12 filter at the o-ring between the filter and the water separator. On inspection it looked fine, it was brand new, but unscrewing, cleaning and re-tightening a little more snugly did the trick.
Rather then purchase an electric pump I closed the fuel line at the tank and blew into the end of the fuel line. The leak was obvious! I also figured out that the primer on the lift pump only works when the pump is in compression- not made clear in the manual. I did not feel comfortable with my reassembly and the primer mechanism appeared to slip past the diaphragm tab on occasion, so I changed out the lift pump. All is good.
Talbot